1,457 research outputs found
Percutaneous pulmonary valve implantation alters electrophysiologic substrate
BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is firstâline therapy for some congenital heart disease patients with right ventricular outflow tract dysfunction. The hemodynamics improvements after PPVI are well documented, but little is known about its effects on the electrophysiologic substrate. The objective of this study is to assess the shortâ and mediumâterm electrophysiologic substrate changes and elucidate postprocedure arrhythmias. METHODS AND RESULTS: A retrospective chart review of patients undergoing PPVI from May 2010 to April 2015 was performed. AÂ total of 106 patients underwent PPVI; most commonly these patients had tetralogy of Fallot (n=59, 55%) and pulmonary insufficiency (n=60, 57%). The median followâup time was 28Â months (7â63Â months). PreâPPVI, 25 patients (24%) had documented arrhythmias: nonsustained ventricular tachycardia (NSVT) (n=9, 8%), frequent premature ventricular contractions (PVCs) (n=6, 6%), and atrial fibrillation/flutter (AF/AFL) (n=10, 9%). PostâPPVI, arrhythmias resolved in 4 patients who had NSVT (44%) and 5 patients who had PVCs (83%). New arrhythmias were seen in 16 patients (15%): 7 NSVT, 8 PVCs, and 1 AF/AFL. There was resolution at mediumâterm followâup in 6 (86%) patients with newâonset NSVT and 7 (88%) patients with newâonset PVCs. There was no difference in QRS duration preâPPVI, postâPPVI, and at mediumâterm followâup (P=0.6). The median corrected QT lengthened immediately postâPPVI but shortened significantly at midterm followâup (P<0.01). CONCLUSIONS: PPVI reduced the prevalence of NSVT. The majority of postimplant arrhythmias resolve by 6Â months of followâup
Influence of spin fluctuations near the Mott transition: a DMFT study
Dynamics of magnetic moments near the Mott metal-insulator transition is
investigated by a combined slave-rotor and Dynamical Mean-Field Theory solution
of the Hubbard model with additional fully-frustrated random Heisenberg
couplings. In the paramagnetic Mott state, the spinon decomposition allows to
generate a Sachdev-Ye spin liquid in place of the collection of independent
local moments that typically occurs in the absence of magnetic correlations.
Cooling down into the spin-liquid phase, the onset of deviations from pure
Curie behavior in the spin susceptibility is found to be correlated to the
temperature scale at which the Mott transition lines experience a marked
bending. We also demonstrate a weakening of the effective exchange energy upon
approaching the Mott boundary from the Heisenberg limit, due to quantum
fluctuations associated to zero and doubly occupied sites.Comment: 6 pages, 3 figures. V3 was largely expande
Cis-regulatory elements of the mitotic regulator, string/Cdc25
Mitosis in most Drosophila cells is triggered by brief bursts of transcription of string (stg), a Cdc25-type phosphatase that activates the mitotic kinase, Cdk1 (Cdc2). To understand how string transcription is regulated, we analyzed the expression of string-lacZ reporter genes covering approximately 40 kb of the string locus. We also tested protein coding fragments of the string locus of 6 kb to 31.6 kb for their ability to complement loss of string function in embryos and imaginal discs. A plethora of cis-acting elements spread over >30 kb control string transcription in different cells and tissue types. Regulatory elements specific to subsets of epidermal cells, mesoderm, trachea and nurse cells were identified, but the majority of the string locus appears to be devoted to controlling cell proliferation during neurogenesis. Consistent with this, compact promotor-proximal sequences are sufficient for string function during imaginal disc growth, but additional distal elements are required for the development of neural structures in the eye, wing, leg and notum. We suggest that, during evolution, cell-type-specific control elements were acquired by a simple growth-regulated promoter as a means of coordinating cell division with developmental processes, particularly neurogenesis.Dara A. Lehman; Briony Patterson, Laura A. Johnston; Tracy Balzer; Jessica S. Britton; Robert Saint and Bruce A. Edga
Multiconfigurational time-dependent Hartree-Fock calculations for photoionization of one-dimensional Helium
The multiconfigurational time-dependent Hartree-Fock equations are discussed
and solved for a one-dimensional model of the Helium atom. Results for the
ground state energy and two-particle density as well as the absorption spectrum
are presented and compared to direct solutions of the time-dependent
Schroedinger equation.Comment: 10 pages, 3 figures, 1 tabl
Optimization of an Alkylpolyglucoside-Based Dishwashing Detergent Formulation.
The aim of this work was to formulate and optimize the washing performance of an alkylpolyglucoside-based dishwashing detergent. The liquid detergent was formulated with five ingredients of commercial origin: anionic (linear sodium alkylbenzenesulfonate and sodium laurylethersulfate), nonionic (C12âC14 alkylpolyglucoside) and zwitterionic (a fatty acid amide derivative with a betaine structure) surfactants, and NaCl for viscosity control. In addition to the plate test, other properties were investigated including ââcloud pointââ, viscosity, and emulsion stability. Statistical analysis software was used to generate a central composite experimental design. Then, a second order design and analysis of experiments approach, known as the Response Surface Methodology, was set up to investigate the effects of the five components of the formulation on the studied properties in the region covering plausible component ranges. The method proved to be efficient for locating the domains of concentrations where the desired properties were met
In situâDirected Growth of Organic Nanofibers and Nanoflakes: Electrical and Morphological Properties
Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes for electrical connection continues to be a significant hindrance toward their large-scale implementation. Here, we demonstrate in situâdirected growth of such organic nanostructures between pre-fabricated contacts, which are sourceâdrain gold electrodes on a transistor platform (bottom-gate) on silicon dioxide patterned by a combination of optical lithography and electron beam lithography. The dimensions of the gold electrodes strongly influence the morphology of the resulting structures leading to notably different electrical properties. The ability to control such nanofiber or nanoflake growth opens the possibility for large-scale optoelectronic device fabrication
DTS-100G â a versatile heterogeneous MPSoC board for cryogenic sensor readout
Heterogeneous devices such as the Multi-Processor System-on-Chip (MPSoC) from Xilinx are extremely valuable in custom instrumentation systems. This contribution presents the joint development of a heterogeneous MPSoC board called DTS-100G by DESY and KIT. The board is built around a Xilinx Zynq Ultrascale+ chip offering all available high-speed transceivers using QSFP28, 28 Gbps FireFly, FMC, and FMC+ interfaces. The board is not designed for a particular application, but can be used as a generic DAQ platform for a variety of physics experiments. The DTS-100G board was successfully developed, built and commissioned. ECHo-100k is the first experiment which will employ the board. This contribution shows the system architecture and explains how the DTS-100G board is a crucial component in the DAQ chain
First limits on the very-high energy gamma-ray afterglow emission of a fast radio burst:H.E.S.S. observations of FRB 150418
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